Traveling rails for carriage

ABSTRACT

In a carriage traveling rail to which a carriage is movably attached, upper ends of a plurality of suspenders are fixed to a ceiling and the suspenders extend downward. A first linear rail member is elongated in one direction and suspended by the suspenders which are arranged with a prescribed interval. A curved rail module is curved in a vertical plane and elongated in the curved direction. The curved rail module is suspended by the suspenders which are arranged with a prescribed interval and includes a curved member having a curved face which is curved in the vertical plane along the elongated direction, and a plurality of second linear rail members elongated in one direction and fixed to the curved member. The second rail members are shorter than the first linear rail member in length relative to the elongated direction. The second linear rail members are in contact with the curved face while being so arranged that adjacent ones of the second linear members are elongated in directions different from each other and end faces in the elongated direction of the adjacent ones of the second linear members oppose each other, so that the carriage travels while being guided by the second linear rail members.

BACKGROUND

The present invention relates to traveling rails on which a carriage ismovably mounted.

Japanese Patent Publication No. 2005-112563A discloses a transportsystem in which an OHT (Overhead Hoist Transport) carriage is suspendedon a rail (carriage traveling rail) suspended on a ceiling and the OHTcarriage is movable along the rail (the carriage is movably attached tothe carriage traveling rail).

Here, when the transport system is used in a clean room for producing asemiconductor or a liquid crystal device, new factories may beestablished in existing buildings or new production facilities may beadditionally established in existing factory spaces so as to expand aproduction capacity and update existing production lines to newproduction lines corresponding to up-to-date devices. In the transportsystem, the rail is generally installed in a horizontal direction in thevicinity of the ceiling and thus the OHT carriage moves in thehorizontal direction. It may be necessary to give a level difference tothe rail in stalled on the ceiling at the time of establishing the newfactories and facilities.

In the transport system disclosed in the above publication, a pluralityof rail members constituting the rail are disposed to be inclined inaccordance with the level difference in portions of the rail of whichthe level varies. At this time, it is necessary to dispose the railmembers while checking an inclination angle of the rail members, therebyincreasing the number of installation processes and making a workingerror easily occur. In order to form a smoothly curved rail, it isnecessary that the rail members disposed in the varied portions areshorter than rail members disposed in the horizontal direction andinclined portions are formed by the use of a plurality of the short railmembers, thereby increasing the number of processes of suspending therail on the ceiling in the inclined portions.

SUMMARY

It is therefore one advantageous aspect of the invention to provide atraveling rail for a carriage having a level difference but capable ofreducing the number of processes and working errors.

According to one aspect of the invention, there is provided a carriagetraveling rail, to which a carriage is movably attached, comprising:

a plurality of suspenders, upper ends of which are fixed to a ceiling,extending downward;

a first linear rail member, elongated in one direction and suspended bythe suspenders which are arranged with a prescribed interval; and

a curved rail module, being curved in a vertical plane and elongated inthe curved direction, the curved rail module suspended by the suspenderswhich are arranged with a prescribed interval and comprising:

a curved member, having a curved face which is curved in the verticalplane along the elongated direction; and

a plurality of second linear rail members, elongated in one directionand fixed to the curved member, the second rail members being shorterthan the first linear rail member in length relative to the elongateddirection, wherein:

the second linear rail members are in contact with the curved face whilebeing so arranged that adjacent ones of the second linear members areelongated in directions different from each other and end faces in theelongated direction of the adjacent ones of the second linear membersoppose each other, so that the carriage travels while being guided bythe second linear rail members.

With this configuration, when the carriage traveling rail has a leveldifference, portions of which the level varies can be connected by theuse of a curved rail module. Here, the curved rail module can be formedby arranging a plurality of second linear rail members in contact with acurved face and fixing the second linear rail members to a curvedmember. Accordingly, at the time of forming the portions of thetraveling rail of which the level varies, it is not necessary to checkthe inclination angles for the second linear rail members, therebyreducing the number of processes and making the working error difficultto occur. In the curved rail module, since the plurality of secondlinear rail members are fixed to the curved member, the curved railmodule can be suspended on a ceiling by supporting the curved railmodule by the use of a suspender at prescribed intervals and it is notnecessary to individually support the plurality of second linear railmembers by the use of the suspenders. Accordingly, the number ofsuspenders is small and the number of processes of suspending the curvedrail module is decreased.

The curved member may be either a convex curved member in which thecurved face is convex toward the second linear rail members or a concavecurved member in which the curved face is convex toward an opposite sideof the second linear rail members.

With this configuration, even when the curved member can be placed onlyat any one of an upside and a lower side of the second linear railmember, both a curved rail module curved to be upwardly convex and acurved rail module curved to be downward concave can be manufactured bythe use of a convex curved member and a concave curved member as thecurved members, thereby connecting all the portions of the carriagetraveling rail of which the level varies by the use of the curved railmodules.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a transport system 1 according toone embodiment of the invention.

FIG. 2 is a side view showing a carriage traveling rail in FIG. 1.

FIG. 3 is a schematic perspective view showing a first linear railmember in FIG. 2.

FIGS. 4A and 4B are schematic perspective views showing curved railmodules in FIG. 2.

FIG. 5 is a section view showing a connecting part between a secondlinear rail and a concave-curved member and a connecting part betweenthe second linear rail and a convex-curved member in FIG. 4.

FIG. 6 is a side view showing the linear rail member and an OHT carriageviewed from a direction that the OHT carriage is transported.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the invention will be describedwith reference to the accompanying drawings.

FIG. 1 is a diagram schematically illustrating a configuration of atransport system according to an embodiment of the invention. Atransport system 1 is installed in a clean room for manufacturing asemiconductor. As shown in FIG. 1, the transport system 1 includes acarriage traveling rail 2 and an OHT carriage 5. The OHT carriage 5moves along the carriage traveling rail 2, and thus workpieces aretransported in each manufacturing process and between manufacturingprocesses.

The carriage traveling rail 2 includes an interprocess rail 6, aplurality of branch rails 7, and a plurality of intraprocess rails 4.The interprocess rail 6 is an annular rail extending in a verticaldirection of FIG. 1 on the left side of a plurality of bays 9 arrangedin the vertical direction of FIG. 1 to perform processes at the time ofmanufacturing a semiconductor. The carriage 5 moves between the bays 9along the interprocess rails 6. A plurality of the branch rails 7 arerails branched from the interprocess rail 6 in correspondence with theplurality of bays 9. The carriage 5 moves from the interprocess rail 6to the branch rail 7 corresponding to the bay 9 of a transportdestination and then, moves up to the upside of each bay 9 along thebranch rail 7. A plurality of the intraprocess rails 4 are connected tothe plurality of branch rails 7 and extend on each bay 9 in an annularpattern. A semiconductor manufacturing equipment 36 for manufacturing asemiconductor and a stocker 37 for stocking a FOUP (Front-OpeningUnified Pod) 34 (see FIG. 6) transported by the OHT carriage 5 areprovided in each bay 9. A port 35 for loading and unloading the FOUP 34(see FIG. 6) is provided in the semiconductor manufacturing equipment36. An unloading port 38 and a loading port 39 for loading and unloadingthe FOUP 34 to and from the stocker 37 are provided in the stocker 37.The OHT carriage 5 moves to the upsides of the port 35, the unloadingport 38, and the loading port 39 along the intraprocess rail 4.Accordingly, as described below, parts manufactured in one bay 9 forperforming a process can be loaded on the FOUP 34 (see FIG. 6) andtransported to another bay 9 for performing another process.

Next, a structure of the carriage traveling rail 2 is described withreference to FIGS. 2 to 5. FIG. 2 is a side view of the carriagetraveling rail 2 of FIG. 1. FIG. 3 is a schematic perspective view of afirst linear rail member 8 of FIG. 2. FIG. 4A is a schematic perspectiveview of a curved rail module 41 of FIG. 2 and FIG. 4B is a schematicperspective view of a curved rail module 42 of FIG. 2. FIG. 5 is asection view of a connecting part between a concave-curved member 10 anda second linear rail member 12 of FIG. 4A and a connecting part betweena convex-curved member 11 and the second linear rail member 12 of FIG.4B.

As shown in FIG. 2, the carriage traveling rail 2 includes a firstlinear rail member 8, the two kinds of curved rail modules 41 and 42,and a suspender 14. As shown in FIG. 3, the first linear rail member 8has a rectangular parallelepiped outer shape and has openings 8 b on twoend faces in an elongated direction thereof. There is formed a space 8 aextending in the elongated direction of the first linear rail member 8and having a slit 8 c both ends of which are connected to the twoopenings 8 b on the lower face of the first linear rail member 8. Asdescribed below, a primary coil 21, a primary core 23, secondary coils24, branch rollers 27, and traveling wheels 28 (see FIG. 6) of the OHTcarriage 5 move within the space 8 a.

As shown in FIGS. 2 and 4A, the curved rail module 41 includes fivesecond linear rail members 12 and a concave-curved member 10. The curvedrail module 41 is curved within a vertical face and elongates in acurved direction. The second linear rail member 12 has a substantiallyrectangular parallelepiped outer shape having a length in the elongateddirection smaller than that of the first linear rail member 8. Thesecond linear rail members 12 have openings 12 b formed on two end facesin the elongated direction thereof. There is formed a space 12 aextending in the elongated direction of the second linear rail member 12and having a slit 12 c both end of which is connected to the twoopenings 12 b on the lower face of the second linear rail member 12. Asdescribed below, the primary coil 21, the primary core 23, the secondarycoils 24, the branch rollers 27, and the traveling wheels 28 (see FIG.6) of the OHT carriage 5 move within the space 12 a.

The concave-curved member 10 has a flat upper face and a lower curvedface 10 a smoothly curved within the vertical face to be convex upwardalong the elongated direction (convex in a direction away from thesecond linear rail members 12). The five second linear rail members 12are fixed to the concave-curved member 10 in contact with the curvedface 10 a so that elongated directions of adjacent second linear railmembers 12 are different from each other. The openings 12 b (end facesin the elongated direction) of the adjacent second linear rail members12 are connected to be opposed to each other. Here, a gap is providedbetween the openings 12 b of the adjacent second linear rail members 12.However, since the gap is small, the carriage 5 is guided and moved tothe five second linear rail members 12 beyond the gap (beyond theopenings 12 b of the adjacent second linear rail members 12). The gapdoes not cause an actual problem. A profile of an end face of the secondlinear rail members 12 is adjusted so as to prevent the gap from beingproduced. The five second linear rail members 5 form a smoothly curvedrail along the curved 10 a as a whole. As shown in FIG. 5, the secondlinear rail member 12 and the concave-curved member 10 are fixed to eachother by mounting, from a side of the concave-curved member 10, a nut 16on a bolt 15 extending through the second linear rail member 12 and theconcave-curved member 10 from a ceiling face of the space 12 a of thesecond linear rail member 12. Here, the second linear rail member 12 andthe concave-curved member 10 are fitted into each other by the use ofthe bolt 15 and the nut 16 with a washer 19 disposed below the ceilingface, and a washer 17 and a spring washer 18 disposed on theconcave-curved member 10 interposed therebetween.

As shown in FIGS. 2 and 4B, the curved rail module 42 includes fivesecond linear rail members 12 and a convex-curved rail member 11. Thecurved rail module 42 is curved within the vertical face and elongatesin the curved direction. The second linear rail members 12 of the curvedrail module 42 are the same as those of the curved rail module 41. Theconvex-curved rail member 11 has a flat upper face and a lower curvedface 11 a smoothly curved within the vertical face to be convex downwardalong the elongated direction (convex toward the second linear railmembers 12). The five second linear rail members 12 are fixed to theconvex-curved member 11 in contact with the curved face 11 a so thatelongated directions of adjacent second linear rail members 12 aredifferent from each other. The openings 12 b (end faces in the elongateddirection) of the adjacent second linear rail members 12 are connectedto be opposed to each other. Here, the gap is provided between theopenings 12 b of the adjacent second linear rail members 12, but the gapis small and the carriage 5 is guided and moved to the five secondlinear rail members 12 beyond the gap. The profile of the end face ofthe second linear rail members 12 is adjusted so as to prevent the gapfrom being produced. The five second linear rail members 12 form thesmoothly curved rail along the curved 11 a as a whole. As shown in FIG.5, the second linear rail member 12 and the convex-curved member 11 arefixed to each other by the use of the bolt 15, the nut 16, the washers17 and 19, and the spring washer 18 in the same manner as the secondlinear rail member 12 and the concave-curved member 10.

Upper ends of a plurality of suspenders 14 are fixed to the ceiling. Thesuspenders 14 extend downward from the upper end. Lower ends of thesuspenders 14 are fixed to both ends of the first linear rail member 8in the elongated direction and fixed to the second linear rail member 12located at both ends of the curved rail modules 41 and 42 in theelongated direction (supported at prescribed intervals). According tothis configuration, the first linear rail member 8, and the curved railmodules 41 and 42 are suspended on the ceiling by the suspenders 14.

As shown in FIG. 2, the carriage traveling rail 2 is formed of a railhaving the level difference. The plurality of first linear rail members8 are disposed and the openings 8 b of the adjacent first linear railmembers 8 are connected to each other in portions of the carriagetraveling rail 2 having a constant level, which extends in thehorizontal direction. In the portions of the traveling rail 2 of whichthe level varies, the curved rail module 41 is disposed adjacent to thefirst linear rail member 8 located in a higher position, and the opening8 b and the opening 12 b are connected to each other, and the curvedrail module 42 is disposed adjacent to the first rail member 8 locatedin a lower position, and the opening 8 b and the opening 12 b areconnected to each other. The curved rail modules 41 and 42 are connectedto each other with the first linear rail member 8 interposedtherebetween.

Here, the curved rail modules 41 and 42 can be formed by arranging thefive second linear rail members 12 on the curved face 10 a and thecurved face 11 a and fixing the five second linear rail members 12 tothe concave-curved member 10 and the convex-curved member 11. Theportions of the carriage traveling rail 2 of which the level varies canbe connected by the use of the curved rail modules 41 and 42, and thusit is not necessary to dispose the second linear rail members 12 whilechecking the inclination angles of the second linear rail members 12 inthe portions of the traveling rail 2 of which the level varies.Accordingly, the number of processes of suspending the curved railmodule is decreased and a working error is difficult to occur. In thecurved rail modules 41 and 42, since the five second rail members 12 arefixed to each of the concave-curved member 10 and the convex-curvedmember 11, it is possible to suspend the curved rail modules 41 and 42by fixing two second linear rail members 12 located at both ends of eachof the curved rail modules 41 and 42 in the elongated direction to thelower ends of the suspenders 14 (by supporting the curved rail modules41 and 42 by the use of the suspenders 14 at the prescribed intervals).Accordingly, it is not necessary to individually suspend the five secondlinear rail members 12 by the use of the suspenders 14, and thus thenumber of the suspenders 14 may be small and the number of the workingprocesses of suspending the curved rail modules 41 and 42 is decreased.

Next, the OHT carriage 5 is described with reference to FIG. 6. FIG. 6is a side view of the linear rail members 8 and 12, and the OHT carriage5 as viewed in a transport direction of the OHT carriage 5. In order toeasily understand FIG. 6, the space 8 a (the space 12 a) in FIG. 6 isdrawn larger than that in FIGS. 3 to 5.

As shown in FIG. 6, the OHT carriage 5 includes the primary coil 21, theprimary core 23, the two secondary coils 24, the two branch rollers 27and the two traveling wheels 28 which move within the spaces 8 a and 12a, and a positioning mechanism 29, a suspension belt 30 and a hoist 31which extend downward beyond openings 8 c and 12 c.

The primary coil 21 and the primary core 23 are provided in asubstantially center of the OHT carriage 5 in a plan view. Meanwhile, inthe linear rail members 8 and 12, a secondary permanent magnet 22extending in the elongated direction is placed in a substantially centerof the ceiling faces of the spaces 8 a and 12 a in correspondence withthe primary coil 21 and the primary core 23.

The two secondary coils 24 are formed in the vicinity of two lateralfaces of each of the spaces 8 a and 12 a in a direction perpendicular tothe elongated direction of each of the linear rail members 8 and 12.Meanwhile, two primary power feeders 25 extending in the elongateddirection of each of the linear rail members 8 and 12 are provided onthe two lateral faces of each of the linear rail members 8 and 12 incorrespondence with the secondary coils 24.

A power supplied to the primary power feeders 25 is supplied to the OHTcarriage 5 as a conductive power conducted to the secondary coil 24 in anon-contact manner. A linear motor including the primary coil 21, theprimary core 23 and the secondary permanent magnet 22 generates atraveling thrust of the OHT carriage 5.

The two branch rollers 27 are placed below each of the secondary coils24. Meanwhile, branch guides 26 are formed adjacent to a branch point(see FIG. 2) between the interprocess rail 6 and the branch rail 7,which protrude in the horizontal direction from the same lateral face asa face on which the primary power feeder 25 is provided below theprimary power feeder 25 in correspondence with the branch roller 27,have a profile of an end face curved downward at an end and extend inthe elongated direction of the linear rail members 8 and 12. The twobranch rollers 27 are integrally movable in the horizontal directionshown in FIG. 6. Only one of the two branch rollers 27 selectivelyengages with the corresponding branch guide 26. According to thisconfiguration, it is possible to choose whether or not to move the OHTcarriage 5 to the branch rail 7 from the interprocess rail 6.

The two traveling wheels 28 are respectively provided below the twobranch rollers 27. A diameter of each of the two traveling wheels has asize exceeding the gap produced between the openings 12 b of theadjacent second linear rail members 12 in the above-mentioned curvedrail modules 41 and 42. The traveling wheels 28 are supported on bottomfaces of the spaces 8 a and 12 a. The traveling wheels 28 move withinthe spaces 8 a and 12 a with the primary coil 21, the primary core 23,the secondary coils 24 and the branch roller 27 by rotation of thetraveling wheels 28. According to this configuration, the OHT carriage 5moves along the linear rail members 8 and 12.

The positioning mechanism 29 performs a positioning operation betweenthe OHT carriage 5 and the port 35. The suspension belt 30 extendsdownward from a lower face of the positioning mechanism 29. The hoist 31is mounted on a lower end of the suspension belt 30. The hoist 31 ismovable in the vertical direction by rolling up or down the suspensionbelt 30.

A gripper 32 for gripping the FOUP 34 is provided on a lower face of thehoist 31. The FOUP 34 is a box in which a semiconductor substrate suchas a silicon wafer internally transported can be put. A flange 33engaging in the gripper 32 is formed on an upper face of the FOUP 34.The gripper 32 grips the FOUP 34 by engagement with the flange 33 andduring the FOUP 34 is transported and the gripper 32 places the FOUP 34on the port 35 and the loading port 39 by disengagement from the flange33 when the FOUP 34 arrives at the port 35 and the loading port 39 of atransport destination.

Here, a transporting operation of the FOUP 34 performed by the OHTcarriage 5 is described. At the time of transporting the FOUP 34, theOHT carriage 5 first moves to the upside of the port 35 at which theFOUP 34 to be transported is placed along the carriage traveling rail 2.The OHT carriage 5 is positioned by the positioning mechanism 29 at theupside of the port 35 of the transport destination. When the positioningoperation is completed, the suspension belt 30 is released and the hoist31 moves downward until the gripper 32 is brought contact with theflange 33 of the FOUP 34. The gripper 32 engages with the flange 33, andthen the suspension belt 30 is rolled up.

Next, the OHT carriage 5 moves to the upside of the port 35 of thetransport destination along the carriage traveling rail 2. The OHTcarriage 5 is positioned by the positioning mechanism 29 at the upsideof the port 35 of the transport destination. When the positioningoperation is completed, the suspension belt 30 is released and the hoist31 moves downward to the port 35 with the FOUP 34. At the time when thelower face of the FOUP 34 reaches the port 35, the FOUP 34 is placed onthe port 35 by disengagement of the gripper 32 from the flange 33. Afterthen, the OHT carriage 5 rolls up the suspension belt 30 and moves alongthe carriage traveling rail 2 in accordance with a subsequent command.An operation of taking the FOUP 34 out of the unloading port 38 and anoperation of transporting the FOUP 34 to the loading port 39 are thesame as the transporting operation of the FOUP 34 performed by the OHTcarriage 5. Accordingly, a description thereof will be omitted.

According to the embodiment described above, when the carriage travelingrail 2 is disposed with the level difference, the portions of thecarriage traveling rail 2 of which the level varies can be connected bythe use of the curved rail modules 41 and 42. Here, since the curvedrail modules 41 and 42 can be formed by arranging the five second linearrail members in contact with the curved faces 10 a and 11 a, and byfixing the five second linear rail members to the curved members 10 and11, it is not necessary to check the inclination angle for each secondlinear rail member 12, and thus the number of working processes isdecreased and the working error is difficult to occur at the time offorming the portions of the traveling rail of which the level varies.

In the curved rail modules 41 and 42, since the five second linear railmembers 12 are fixed to each of the concave-curved member 10 and theconvex-curved member 11, it is possible to suspend the curved railmodules 41 and 42 on the ceiling by fixing the second linear railmembers 12 located at both ends of each of the curved rail modules 41and 42 in the elongated direction to the lower ends of the suspenders14. Accordingly, it is not necessary to suspend the five second linearrail members 12 by the use of the suspenders 14 separately, and thus thenumber of the suspenders 14 may be small and the number of the processesfor suspending the curved rail modules 41 and 42 is decreased.

The curved rail module 41 having a rail curved to be convex upward andthe curved rail module 42 having a rail curved to be convex downward canbe formed by using the concave-curved member 10 and the convex-curvedmember 11 as the curved member. Accordingly, even when the curved membercan be provided only at the upside of the second linear rail member 12,all the portions of the carriage traveling rail 2 of which the levelvaries can be connected by the use of the curved rail modules 41 and 42.

In the above-mentioned description, the preferred embodiment of theinvention has been described, but the invention is not limited to theabove-mentioned embodiment. Various changes and modifications may bemade within the scope without departing from the claims. For example, inthe embodiment, the five second linear rail members 12 are used to formeach of the curved rail modules 41 and 42, but the number of the secondlinear rail members 12 is not limited to five. An optimum design valueselected in accordance with the degree of the rail level difference, andlengths of the curved face 10 a and the second linear rail members 12 inthe elongated direction may be applied to the number of the secondlinear rail members 12.

In the embodiment, in the portions of the carriage traveling rail 2 ofwhich the level varies, the curved rail module 41 is connected to thefirst linear rail member 8 located at the higher position, the curvedrail module 42 is connected to the first linear rail member 8 located atthe lower position and the first linear rail member 8 is connectedbetween the curved rail modules 41 and 42, but the invention is notlimited to them. The curved rail module 41 may be directly connected tothe curved rail module 42 in portions of carriage traveling rail 2having a small level difference. On the contrary, the plurality ofcurved rail modules 41 and the plurality of curved rail modules 42 eachmay be continuously connected in portions of the carriage traveling rail2 having a large level difference.

In the embodiment, the carriage traveling rail 2 for transporting theOHT carriage 5 is described, but the invention may be applied tocarriage traveling rails for transporting other kinds of carriages suchas an OHS (Over Head Shuttle).

In the above-mentioned description, the printer according to theembodiment has been described, but the invention is not limited to allthe above-mentioned embodiments. Various changes and modifications maybe made within the scope without departing from the claims.

The disclosure of Japanese Patent Application No. 2006-187670 filed Jul.6, 2006 including specification, drawings and claims is incorporatedherein by reference in its entirety.

1. A carriage traveling rail, to which a carriage is movably attached,comprising: a plurality of suspenders, each of which is extendeddownward from a ceiling; a first linear rail member, having a firstlongitudinal dimension and suspended by the suspenders; and a curvedrail module, comprising: a curved member, suspended by the suspendersand having a curved face which is curved in a vertical plane along anelongated direction thereof; and a plurality of second linear railmembers, each of which is fixed to the curved member and has a secondlongitudinal dimension shorter than the first longitudinal dimension,wherein: the second linear rail members are arranged along the curvedface such that adjacent ones of the second linear members are elongatedin directions different from each other and longitudinal end faces ofthe adjacent ones of the second linear members oppose each other.
 2. Thecarriage traveling rail as set forth in claim 1, wherein the curvedmember is either a convex curved member in which the curved face isconvex toward the second linear rail members or a concave curved memberin which the curved face is convex concaved from the second linear railmembers.